Chouteau County, Montana
Shrink-swell clay limits houses without basements on 39% of Chouteau County's mapped land, a higher share than 86% of US counties and the 8th highest of 53 Montana counties. A shallow water table limits basements on 2%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list no flood losses here since 2016. 64% of homes were built before 1980, against 50% nationally; the median home dates from 1968.
Data as of October 13, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, October 13, 2026
of homes built before 1980
Soil under Chouteau County
| Expansive clay (limits slab homes) | 38.8% |
| High water table (limits basements) | 2.3% |
| Septic fields very limited | 84.8% |
| Clay swell (LEP, by area) | 5.4% |
| High-swell land (LEP 6%+) | 38.4% |
| Mapped soil | 2,520,857 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Telstad | 7% | n/a |
| Hillon | 6% | n/a |
| Scobey | 6% | n/a |
| Bearpaw | 6% | n/a |
| Kevin | 5% | n/a |
| Joplin | 5% | n/a |
How we count · survey areas MT615 (2025-08-30)
What the numbers mean here
Clay swell averages a linear extensibility of 5.4% by land area here, and 38% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 39% of the mapped land.
Rain over the 12 months to August 2026: 13.88 in, 0.05 in above the 1991-2020 average year of 13.83 in.
USDA rates 85% of the land very limited for septic absorption fields.
Drought
0% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 44 of the last 52 weeks; the most was 100% of its area, in 22 weeks, most recently on the June 23, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 0% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
FEMA's flood data list no flood losses in Chouteau County since 2016.
Rain
| Average year, 1991-2020 | 13.83 in |
| 12 months to August 2026 | 13.88 in (+0.05) |
| 2025 | 12.84 in (-0.99) |
| Wettest year since 1895 | 1975: 22.98 in |
| Driest year since 1895 | 1904: 7.64 in |
| Days with 1 inch or more, normal at LOMA (5 mi away) | 0.7 |
Homes
| Housing units | 2,885 |
| Median year built | 1968 |
| Built before 1980 | 64% |
| Built 2000 or later | 11% |
| Owner-occupied | 68% |
| Median value, owner-occupied | $207,800 |
| Single-family detached | 78% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Liberty County, MT | 53 mi | 34% | 3% |
| Hill County, MT | 54 mi | 29% | 3% |
| Cascade County, MT | 58 mi | 35% | 2% |
| Judith Basin County, MT | 59 mi | 37% | 4% |
| Fergus County, MT | 72 mi | 51% | 3% |
| Blaine County, MT | 77 mi | 44% | 2% |
| Toole County, MT | 80 mi | 29% | 3% |
| Teton County, MT | 86 mi | 23% | 8% |
Sources: USDA SSURGO (August 30, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status